Future building materials

Written by Robert McCaffrey Editorial Director, Global Cement Magazine

31 October 2017

We at Global Cement have our eyes on a number of different industries, primarily in the building materials sector. We get to see all the latest innovations in cement and concrete, of course, but also those in the insulation, cement-board and gypsum wallboard industries. We are ‘materials agnostic,’ since some materials can substitute for each other quite well (for example different types of insulation provide the same level of performance), whereas it seems that at other times one material offers clear advantages over another in a specific application (for example the use of slag-based concrete as gravity dam foundations, due to the low heat of hydration of the cement).

We also get to see some incipient trends, and how they eventually transpire. For example, alternative fuels are a maturing trend in some parts of the industry, but are still ‘the new thing’ in other areas: As shown on page 54 of this issue, Egypt uses less than 5% of biomass-based fuels, compared to a 16% global average (and 40% best practice). We have also seen a strong trend in the last few years towards reducing the clinker factor. After all, when you can replace costly clinker with cheaper and more environmentally-benign substitutes (and make better concrete), why wouldn’t you? If your local regulations allow it, of course.

So, what other trends are coming down the line, and what can we see for the future of building materials? Well, a quick glance at my favourite graph, below, may give you an indication of two major trends: that building materials will have less embodied energy (they will be more energy-efficient to produce) and that they will also have less embodied CO2. Despite the fact that many climate modelling programmes have now been acknowledged to ‘run hot’ and to over-estimate the degree of future global warming (probably due to an over-sensitivity of the models to the global warming potential of CO2), there is no doubt that CO2 is firmly in society’s sights as the main culprit of global warming. We have seen some consumers shying-away from materials with high embodied CO2 (for example requesting the use of lower-clinker cement for concrete foundations) and this is a trend we expect to continue.

When the cost of energy is high, those building products that can reduce energy consumption can gain a premium in the market. Concrete justly claims to have a high heat capacity and can provide thermal stability to buildings, while insulation can of course slow the transmission of heat from one area to another. Phase change materials (such as wax globules) incorporated into building materials - such as concrete - absorb heat during the day and let it out at night and can emulate the effects of insulation, but there’s a long way to go before the technology becomes widespread.

Gypsum wallboard offers a cheap, lightweight, perfectly flat, fire-resistant wall (and ceiling) surface that can be installed with relatively low skill and at high speed. Its main weakness is in its poor response to moisture (it can grow mouldy and can also sag). Cement-based boards are inherently and permanently moisture- and mould-resistant, but we’d like to see cement-based boards add insulating properties, improved acoustic attenuation, active moisture management and greater control and improvement of indoor air quality (as do other boards). There is a lot of potential for adding value to cement-based boards, and this will be discussed in depth at the 3rd Global Boards Conference in London on 22-23 January 2018.

In the future, we might see a modified tilt-up or prefabrication approach to building construction, where a low-or-no clinker, recycled and recyclable ‘concrete’ with added insulation and phase change materials offers all-round performance at low cost. Since glow-in-the-dark and translucent concrete already exist, this is actually not such a leap. Global Cement 2049 here we come!